Fix corner case in cleanup of transactions using SSI.
When the only remaining active transactions are READ ONLY, we do a "partial
cleanup" of committed transactions because certain types of conflicts
aren't possible anymore. For committed r/w transactions, we release the
SIREAD locks but keep the SERIALIZABLEXACT. However, for committed r/o
transactions, we can go further and release the SERIALIZABLEXACT too. The
problem was with the latter case: we were returning the SERIALIZABLEXACT to
the free list without removing it from the finished list.
The only real change in the patch is the SHMQueueDelete line, but I also
reworked some of the surrounding code to make it obvious that r/o and r/w
transactions are handled differently -- the existing code felt a bit too
clever.
Dan Ports
Branch
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master
Details
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http://git.postgresql.org/pg/commitdiff/326b922e8b2d65257a635b5f80e5de0f15dffd3a
Modified Files
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src/backend/storage/lmgr/predicate.c | 26 +++++++++++++++++++++++---
1 files changed, 23 insertions(+), 3 deletions(-)